This was one of my first Romantic type Animes I have watched.
I had always heard good things about this Anime, and thought I should give it a shot.
Turns out it is one of the best romantic type Animes out there. With a great story line, charecter development, the whole thing about this Anime was perfect!
The animation is beutiful, very clear animation.
Mizuho Kazami—a beautiful young woman—came to a high school in a mountainous area as a Japanese Language teacher; however, she is actually a representative sent by the Galaxy Association on a mission to observe the Earth, and make sure its civilization wasn't going in any wrong directions. Her troubles start when Kei Kusanagi—one of her students—accidentally discovers her true identity. In order to keep her true identity a secret from everyone, Mizuho Kazami and Kei Kusanagi get married. Living together in secret, can they keep their relationship from Kei's classmates?

There is 12 episodes in all, but there is also a 13th episode witch is an OVA.
There is also a prequel, called Onegai Twins.Its a seperat storyline, except with all the original charecters from Onegai Teacher making some short appearances here and there.
I rate this Anime as a 10/10
Heres a nice little video to show you more about it:
- Jamezterr